POLYMERIC STRUCTURES AS COLD FLOW IMPROVERS FOR WAXY RESIDUAL FUEL-OIL

Acrylic and methacrylic acids were esterified with dodecyl, hexadecyl and NAFOL 20(+) (C-av = 21) alcohols. The monomers thus prepared were copolymerized with C-18 alpha-olefin at different molar ratios. The co polymers were purified, characterized and then assessed as cold flow i mprovers for a high-pour waxy residual fuel oil (RFO) by pour point an d rheological measurements. The asphaltene, resin and wax contents of the RFO as well as the carbon number distribution of the wax fraction were determined. The results show that only the polymeric structures w ith long side chains of NAFOL 20(+) have the potential to decrease the pour point and improve the rheological properties of the fuel oil. Th e storage stability of the treated RFO is good up to 3 days but then d iminishes steadily. The effectiveness of the prepared additives is dis cussed on the basis of structure in relation to the fuel oil compositi on. (C) 1997 Elsevier Science Ltd.